Optoelectric devices and electronic components having microelectronic, optoelectronic or photonic components or devices (such as, lasers, for example), are often mounted on bases (assemblies) that consist of a plurality of stacked, dissimilar materials. In such devices, a component is typically mounted to a (first) material that is, in turn, secured to a second, dissimilar, material; such dissimilar materials being attached, using solder, an adhesive, or the like. During the attachment (e.g.,) soldering process, the electronic assembly is exposed to an elevated temperature (e.g., high enough to cause the solder to re-flow) and subsequently cooled down to a lower temperature. The different coefficients of thermal expansion (CTE) in dissimilar materials cause the materials to expand (or contract) at different rates in response to changes in temperature. As a result, the base (assembly) can experience appreciable (residual curvature). At the same time, proper operation of a photonic device requires precise optical alignment between and among the devices, lensed fibers, etc. mounted to the first material. For example, a lateral misalignment of only 0.5 .mu.m between the lightguides (e.g., a laser and a lensed optical fiber) will render the optoelectric device inoperable.
Bowing of the base (assembly) is currently compensated for by aligning the various optical components mounted on the base after the assembly is manufactured. This procedure, referred to as active alignment, is costly and time consuming. Moreover, active alignment only addresses the misalignment before the electronic device is installed or deployed for use; after which deviation in the flatness of the base may not be corrected.
It is thus desirable to provide a method for controlling the bowing of a multi-material assembly that overcomes the above-described shortcomings of the prior art.